(a) Field of the Invention
The present invention relates to an SIP-based user mobility providing apparatus and method using user location information obtained by a sensing apparatus.
(b) Description of the Related Art
There are a variety of networks having different performances and applications for communication services. Users are provided with the communication services using various kinds of terminals. With the development of wired and wireless communication techniques, the users want to select communication infrastructures providing the communication services according to their preferences.
The development of wired and wireless communication networks and a user's desire for being provided with the communication services whenever and wherever the user wants, creates a service environment in which various communication networks coexist in an arbitrary place. In this service environment, the user can use various network services depending on a place where the user uses the services, a moving speed, the kind of information the user wants to use, a performance level, and costs. Furthermore, a user terminal used for communications can have various forms and a choice of a terminal may affect a choice of a communication network. The user has an inclination in utilization of communication services in the aforementioned service environment.
A session initiation protocol (SIP) is a call signaling protocol of an application layer, which provides multimedia session initiation, exchange of session information, and cancellation of session. The SIP allows a user to be provided with communication services using a uniform resource identifier (URI) irrespective of a physical position of a user or a user terminal. That is, a service based on a user's preferences can be provided by several service features in an SIP-based multimedia service environment. Furthermore, services that allow a user to select a communication terminal according to his/her taste are proposed. For example, a receiving terminal for the wired/wireless telephone, E-mail, facsimile, and SMS service can be chosen according to a condition designated by a user. For this, an SIP service network has a separate database that stores user's preferences using for initiation of a communication session.
However, the above-described service can be provided only when the user has a designated terminal or he/she is in a place where the terminal exists. That is, if an arbitrary user provides his/her preferences for services to the SIP service network, a call is accomplished only when the user is located beside a terminal that is designated such that it receives the call at the instant of time when someone attempts to make the call.
Accordingly, there has been proposed a ubiquitous service by which users can be provided with information or services they want in any place using various devices having a computing function that exist in any space. For the ubiquitous service, it is required to collect various contexts of users in order to conjecture psychological states and thoughts of the users and provide services they need.
To grasp the states of the users, various sensing apparatuses are required. There are various sensing apparatuses depending on kinds of information the apparatuses should collect.
Current selective services based on a user's preferences are provided depending on only preference information that has been designated by the user. Thus, the information can designate a terminal for receiving a call only when a designated condition, such as a condition that ‘a call is received by a specific terminal at a specific time zone’ or a condition that ‘a call satisfying a specific condition is sent to voice mail’, is satisfied. However, the call does not arrive at a corresponding user when the user is not located near the terminal.
Furthermore, terminals to be used for services using the SIP must be registered before a communication session is initiated. The SIP Registration cannot be spontaneously carried out when there is no user's intention. In particular, when many unspecified persons share one terminal, it is impossible to conjecture users and carry out the SIP registration. In the case of originating a call, the SIP registration is performed at the instant of time when a user signifies his/her intention to make a call using a terminal, such that he/she uses the terminal, clicks a button or a mouse, or uses a keyboard, and then a session is initiated. In the case of terminating a call, however, when the SIP registration has not been carried out by SIP user agent, any attempt to execute a communication is not received. Thus, a terminating part cannot carry out the SIP registration in time because the terminating part cannot be aware of the time when the terminating part is requested to receive a call. When the terminating part uses his/her own terminal, the SIP registration can be performed when the terminal is turned on or the terminating part previously sets the SIP registration. However, when many persons share one terminal or a user uses an arbitrary terminal in an arbitrary place, the user should carry out the registration using the several terminals. This considerably restricts the communication service using the SIP.